The present invention relates to a device for locking at least one door element in an opening to a space, wherein the device comprises an operating member arranged outside the space, which is arranged to allow, by a motion transmission mechanism, displacement of a locking bar, arranged inside the space, between a first position when the locking bar allows an opening of the door element and a second position when the locking bar connects the door element to a second element such that an opening of the door element is prevented and a lock allowing locking of the locking bar in said second position.
By a door element is meant a door, cover or the like which may be used for closing an opening to a space of an arbitrary kind. In many cases, locking devices for door elements usually are countersinked in recesses provided in the door element. Such recesses result in that the original thickness of the door element and thereby the strength decreases in that area, which is utilised by thieves.
Other kinds of locking devices are arranged outside the door element. Such locking devices may, for example, comprise a locking bar which has one end attached to the door and a second end, which may be fixedly locked to a rigid wall element adjacent to the door, for example, by means of a pad lock. Such locking devices may easily be broken to open, for example, by a hydraulic cutter which has the capacity to cut of steel with a thickness of up to 15 mm. Alternatively, one end of a heavy wire may be attached to the locking bar and the second end to a vehicle, whereafter the vehicle may pull out the locking bar.
Locking devices, which substantially have its locking mechanism arranged on the inside of a door element, provides the best protection against burglary from the outside. However, these locking devices do not eliminate the risk that a thief hides inside or enters a space, which, for example, may be a storage space or a container. Thereafter, the thief may dismount the locking device from the inside. Alternatively, the thief may enter, for example, a storage room, via a window, with the purpose of from the inside dismounting the locking device to facilitate the possibility ton take out the stolen goods.
FR 2 533 961 shows a locking device having a locking mechanism provided on the inside of a door. The rotary motions of an operating member on the outside of the door are transmitted, in this case, to a rotary motion of a gear wheel on the inside of the door. The rotary motions of the gear wheel are transmitted to a displacement motion of a locking bar, via a toothed surface provided thereon, between a door blocking and a not blocking position. A lock is arranged to lock the locking bar in the blocked position. In order to control the displacement motions of the locking bar, metal plates are provided, which are so shaped that they form rectangular channels in which the locking bar is displaceably provided. One such metal plate is arranged on the inside of the door and another on the inside of an adjacent wall. In order to attach these inwardly provided metal plates, corresponding external metal plates are provided on the outside of the door and on the outside of said adjacent wall. These external metal plates comprise fixed soldered bolts extending through the door and the adjacent wall and through holes in the internal metal plates. Thereafter, nuts are provided on the threaded portions of the bolts in order to fix the internal metal plates to the inside of the door and the adjacent wall and thereby said guide channel of the locking bar. For a thief hidden at the inside of the door, it is very simple to screw off said nuts and to disengage the internal metal plates and thereby the locking bar. Furthermore, the gear wheel and the lock are unprotected against attacks from the inside of the door.
The object of the present invention is to provide a device for locking a door element such that it becomes very difficult for a thief to force the locking device both from the outside and from the inside of the door element.
This object is achieved by the initially mentioned device which is characterised in that it comprises a protective housing which is arranged to encase the locking bar and the parts of the lock and the motion transmission mechanism that are arranged inside the space. By such a protective housing covering sensible parts of the device, attacks on these parts are considerably more difficult. Preferably, the protective housing is manufactured of thick hardened steel. Another advantage by protecting said substantially moveable parts of the device, is that one prevents the internal locking mechanism from being blocked by unfixed goods provided in the space, which may be the case, for example, in a container.
According to a preferred embodiment of the present invention, the protective housing is attached to at least one internal wall surface of the space. Thereby, the protective housing may obtain an uncomplicated and stable fixation. Preferably, the protective housing is attached to said internal wall surface by means of a non-dismountable attachment means. Thereby, it is essentially more difficult for a thief to dismount the protective housing from the inside in order to reach and break open the locking mechanism. Such non-dismountable attachment means may be bolts having heads which preferable are countersinked in a mounted state and having such a shape that they are difficult to grip. Such non-dismountable attachment means may also comprise rivets or welding.
According to another preferred embodiment of the present invention, the protective housing comprises a channel in which the locking bar is displaceably provided. Such a protective housing thereby also may work as guiding element to the locking bar. The protective housing may comprise at least two separate parts and that a first part of the protective housing is attached to an internal wall surface and that the second part of the protective housing is attached to an internal wall surface of said second element. Since the locking bar extends between the door element and the second element, it is suitable that the protective housing is arranged as two separate parts. However, the parts of the protective housing will lie close to each other in the closed position of the door element so that they form a continues channel so that the locking bar may be displaced to its second position. Alternatively, the protective housing may be provided as a single part, which is attached to the door element or the adjacent element. The second element may comprise a second openable door element or a rigid wall element. When double door elements are used, the two door elements may be locked together by the locking bar. For a single door element it is suitable that the locking bar locks the door element in relation to an adjacent rigid wall element.
According to another preferred embodiment of the present invention, it comprises coupling means, which is arranged to restrict the force, which the operating member, via the motion transmission mechanism, is allowed to transmit to the locking bar. Thereby, the risk is prevented that a thief by suitable tools from the outside provides a such a heavy force onto the operating member that the locking bar is displaced and deforms the locking mechanism. Such coupling means may comprise a suitable kind of safety clutch. Advantageously, the motion transmission mechanism is arranged to transmit a rotary motion of the operating member to a reciprocal displacement motion of the locking bar. Preferably, the operating member is a rotateable wheel or crank arranged on the outside of the door element. The operating member is connected to a suitable motion transmission mechanism which transforms the rotary motion of the operating member to a reciprocal motion of the locking bar between said first and second position. Preferably, the motion of the locking bar is linear.
According to another preferred embodiment of the present invention, the locking bar has a front portion provided in a displacement direction, said front portion comprises at least one chamfering. By such a chamfering, the risk is eliminated that the locking bar tilts and jams during the displacement motion in the channel. Especially when the protective housing consists of two pieces and the channel is divided, such a chamfering brings about that the parts of the channel are centred to a desired position in relation to each other during the displacement motion of the locking bar.
According to another preferred embodiment of the present invention, the lock comprises a bolt, which is insertable in a recess in the locking bar in order to lock the locking bar in said second position. Preferably, such a lock comprises a lock body extending through the door. On the outside of the door element, a key activates the lock so that the bolt, which is provided on the inside of the door, is displaced in or out of said recess. Preferably, the lock is a 9-lever tumbler lock. Such a lock is a high security lock, which is approved to be used in safes. The key of the lock is protected against an unauthorised copying. Furthermore, the lock has a barrier, which prevents insertion of optical means for photographing the inside with the purpose of manufacturing an unauthorised key.
According to another preferred embodiment of the present invention, the device comprises a protecting plate arranged outside the space for covering at least a part of a slit provided between the door element and said element, which part of the slit the locking bar internally extends passed in its second position. Preferably, such a protecting plate has an extension along the slit, which at least corresponds to the width of the locking bar. By such a protecting plate, it is made more difficult for a thief to insert a cutting tool in the slit with the purpose to cut off the locking bar.